This year, 13.5 tons of ground beef and steak were recalled just before July 4 because they were potentially tainted with E. coli — a bacteria that causes abdominal cramps, diarrhea, and vomiting. Consumer Reports investigated further to see what other bacteria were in ground beef.

The magazine purchased 300 packages of ground beef from 103 grocery stores across the country, including both grass-fed and antibiotic-laden beef. They analyzed these samples and found that more than 80 percent of “conventionally raised” (raised using antibiotics) ground beef contained five types of bacteria — E. coli, clostridium perfringens, salmonella, enterococcus, and staphylococcus aureus. Less than 60 percent of grass-fed beef contained these bacteria.

The study also found that conventionally raised beef had more superbug bacteria that are resistant to three or more classes of antibiotics. Only six percent of grass-fed beef contained superbugs.

It is recommended to cook ground beef to at least 160 degrees Fahrenheit to reduce the risk of food poisoning.